Human IL-22BP/Fc Chimera Interleukin 22 binding protein (IL-22BP), also known as cytokine receptor family (CRF) 2-10, CRF2-X, and IL-22 RA2, is a secreted glycoprotein belonging to the type II cytokine receptor family. The IL-22BP gene has been localized to chromosome 6 near the gene for IFN-£^ R1. It encodes a precursor protein of 231 amino acid (aa) residues with a 21 aa putative signal peptide and five potential N-linked glycolsylation sites. IL-22BP lacks a transmembrane and cytoplasmic domain and is most closely related to the extracellular domains of IL-22R (CRF2-9) and IL-20R (CRF2-8), sharing 33% and 34% aa sequence identity, respectively. It also shares sequence homology with the extracellular domains of IL-10R (29%), IL-10 Rb (30%), the IFN receptors (23-25%) and tissue factor (26%). IL-22BP antagonizes IL-22 activity by specifically binding IL-22 with high affinity and blocking its interaction with the cell surface IL-22 receptor heteromeric complex composed IL-22R and IL-20R. IL-22BP is expressed in multiple tissues. The

he recombinant mature human IL-22BP/Fc chimera is a disulfide-linked homodimeric protein. Based on N-terminal amino acid sequencing, the mature protein starts at Thr 22 and has a calculated molecular mass of 51.3kD. As a result of glycosylation, the recombinant monomer migrates as an approximately 75-80kD protein in SDS-PAGE under reducing conditions.

Purity

90%, as determined by SDS-PAGE and visualized by silver stain.

Endotoxin

1.0 EU/ug of the cytokine as determined by the LAL method.

Activity

Measured by its ability to bind rhIL-22. Immobilized rhIL-22BP/Fc at 10ug/ml (100ul/well) can bind rhIL-22 with a linear range of 12.5-0.8 ng/ml in a functional ELISA.

Form

Lyophilized from a 0.2um filtered solution in PBS.

Reconstitution

It is recommended that sterile PBS be added to the vial to prepare a working stock solution of no less than 100ug/ml. The carrier-free protein should be used immediately upon reconstitution to avoid losses in activity due to non-specific binding to the inside surface of the vial. For long term storage as a dilute solution, a carrier protein (e.g. 0.1% HSA or BSA) should be added to the vial.

Storage

Lyophilized samples are stable for greater than six months at -20°C to -70°C. Upon reconstitution, this cytokine, in the presence of a carrier protein, should be stored under sterile conditions at -20°C to -70°C in a manual defrost freezer for three months without detectable loss of activity. Avoid repeated freeze-thaw cycles.

Important Note

This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.